1. Technical Field
The present disclosure of invention relates to a curved frame and a curved display device having the curved frame. More particularly, the present disclosure of invention relates to a curved frame for defining and/or securing a predetermined curvature for an image display panel (one having an image driving, backlighting portion) and to a curved display device having the curved frame.
2. Discussion of Related Technology
In recent years, as thin panel display devices such as liquid crystal display (LCD) devices have come to be more commonly used as display devices of television receivers, home movie theaters, computers (e.g., those used for high definition gaming) and so on, the screens of flat panel versions of such thin panel display devices (e.g., LCD devices) are tending to become increasingly bigger. But one problem with increasingly larger and flat panel LCD or other such thin profile screens is that the viewing angle differences between the state where the viewer is focusing on the center portion of the screen (wherein the normal to the screen surface and the viewer's line of sight (LOS) are basically coincident) and where the viewer is focusing on the left and/or right far edges of the flat screen (wherein the normal to the screen surface and the viewer's LOS are substantially not coincident) increases.
In this specification, the technical term “viewing angle” is defined as the angle present between the line of sight (LOS) of the viewer focusing on a particular surface region of the screen and the surface tangent plane present at the intersection of the line of sight and the focused upon surface region. The difference between the central and the extreme left or right edge viewing angles is defined as and used to mean the “viewing angle difference” (VADmax).
Another problem with large-scale flat panel television screens and the like is that glare off the screens from ambient light sources (e.g., room lamps) also tends to increase with increase of flat panel screen size.
The problems of difference in viewing angles and excessive glare can be corrected by curving the screen into a concave shape.
However, even when the viewing angle difference is improved (reduced) by a liquid-crystal panel with a concavely curved screen (referred to as “concavely curved liquid-crystal panel” below), the traditional approach is to use a flat panel backlighting unit with a same structure as that used for the conventional flat liquid-crystal panel. When this is done, there is a new problem, namely, that the uniformity of the light intensity that is emitted from the light source inside the flat panel backlighting unit is lost in particular at the peripheral edges of the concavely curved liquid-crystal panel. As a result, the image quality (e.g., brightness) of the concavely curved liquid-crystal panel at the left and right edges becomes lower than that of the screen of a conventional flat panel liquid-crystal display device.
One proposed countermeasure for solving this problem while using the flat panel style backlighting design is to enlarge the space between the backlighting light source and the curved screen so that difference in backlighting intensity is lessened. However, this causes the overall display device to become undesirably larger in volume occupied thereby. Such increase in overall volume tends to increase shipping, handling and packaging costs. It also tends to increase the weight of the device as shall become clearer from the below discussion.
It is to be understood that this background of the technology section is intended to provide useful background for understanding the here disclosed technology and as such, the technology background section may include ideas, concepts or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to corresponding invention dates of subject matter disclosed herein.